Pebble Technology has picked up Series A funding to the tune of US$15 million as the company celebrates its first year after being crowd funded via Kickstarter.

Charles River Ventures (CRV) is backing the startup, with partner George Zachary spearheading the deal. According to one of his tweets this morning, Pebble represents his 24th investment. The prior 23 companies — which include Google-acquired Jambool, Adobe-acquired Sandcastle, Twitter, and Yammer — have netted him about US$1 billion after consuming US$160 million it capital costs.

In ~18 years, got ~25K pitches, met 3.5K startups, funded 25. First 23 consumed $160M of total capital and returned $1B. Thank you founders.

It has shipped nearly 70,000 smart watches since it began production, and is planning on expanding its 18-person, Palo Alto-based team to focus on supporting third-party developers that are creating apps for Pebble. All of the 12 positions up for offer are for design or development roles; however, four of those are for internships.

The company's focus on third-party apps is more evidently seen in the supported release of the RunKeeper app that it had featured in its original Kickstarter project last year. That app was released earlier this month.

At the same time, Pebble has announced further updates to its progress. After releasing its preview Watchface software development kit (SDK) last month, it has extended support to include two-way communication between devices in the newly rebranded PebbleKit SDK and its associated API reference documentation. The SDK remains in preview form, with Pebble disclaiming that it is a proof-of-concept release only, and that code written using it could possibly "negatively impact stability of PebbleOS, and, in the worst case, brick a watch".

Already, a number of users have created Pebble applications that can retrieve weather data from the internet via a Bluetooth-tethered smartphone. Previously, developers had used workarounds in Pebble's native music control application to increase the watch's functionality. The SDK also includes a couple of examples to provide developers with basic concepts and some inspiration.

One example includes being able to develop a "link" between two Pebbles by touching their respective NFC-enabled smartphones together. Once the link is established, pressing a button on one watch will cause the other to vibrate. While it's a simple example, it opens the door to potential private messaging apps, or even complete multiplayer games over watches.

Although the SDK will provide developers with better tools to develop two-way communication between Pebbles and smartphones, it still does not provide access to all core features of the smart watch. For instance, accelerometer and magnetometer sensor data is not available, meaning applications like home-brewed fitness apps mimicking the Jawbone or Fitbit still cannot be developed.

While Pebble works to extend its SDK to support these missing features, it has not left sports developers without assistance. It has also developed a Sports API to help developers quickly build on top of the built-in apps on the Pebble watch that are designed for time and distance-based activities. Developers can cut down on the amount of coding required to send information to the smart watch by using PebbleKit libraries, instead of creating everything from scratch.

Not everything has been smooth sailing for the Pebble team, though. At the time of its initial Kickstarter, it estimated that Pebble watches would arrive in customer hands by September 2012. Although a large number of black Pebble watches have shipped, those who ordered coloured versions are experiencing significant delays, coupled with customer frustration over the misconception that its Kickstarter was a "pre-order" system (Pebble does have a pre-order system now, but it is a separate to its Kickstarter campaign, and has an estimated delivery date of late June 2013).

Red Pebble watches began shipping at the end of April, and the team has said that its orange Pebbles are now in production, with shipping expected to begin next week. Grey and white Pebbles are expected to be close behind.